Emerg Med J 25:717-721 doi:10.1136/emj.2007.053751
  • Original Article

Limited analgesic efficacy of nitrous oxide for painful procedures in children

  1. F E Babl,
  2. E Oakley,
  3. A Puspitadewi,
  4. L N Sharwood
  1. Emergency Department, Royal Children’s Hospital, Murdoch Children’s Research Institute and University of Melbourne, Melbourne, Australia
  1. Dr F E Babl, Emergency Department, Royal Children’s Hospital, Parkville, Victoria 3055, Australia; franz.babl{at}
  • Accepted 10 February 2008


Study objective: Nitrous oxide (N2O) is an attractive agent for procedural analgesia and sedation of children in the emergency department (ED). Despite increasing use, efficacy data for painful procedures are limited. This study aimed to determine pain scores during ED procedural sedation with N2O in the ED setting.

Methods: Prospective observational study of N2O use as a sole agent for procedural analgesia at a tertiary children’s hospital ED. Pain scores were obtained from patients and parents using visual analogue or faces scales, as appropriate. Parent and staff satisfaction with sedation and analgesia were assessed.

Results: 124 children aged 1–17 years (mean 8.1) underwent procedural analgesia with N2O for 131 procedures. Most procedures were orthopaedic (44%) or laceration repair (30%). In 51% of patients (95% CI 42% to 60 to 23%) pain scores remained unchanged and in 34% (95% CI 26% to 43%) pain scores increased. Overall, 34% (95% CI 26% to 43%) patients had intraprocedural scores of 50 mm or greater and 21% (95% CI 14% to 29%) had pain scores of 70 mm or greater. Some procedures such as fracture reduction had a larger proportion of patients with high pain scores or 50 mm or greater (45%) and 70 mm or greater (29%). Staff rated both sedation and analgesia as “adequate” in 92%. Parents contacted in follow-up were satisfied or very satisfied with procedures in 96% and sedations in 93%.

Conclusion: Data indicate that parents and staff are generally satisfied with N2O for procedural use in the ED. The efficacy of N2O as a sole agent in very painful procedures is limited.


  • Funding: Grant support was received from the Victor Smorgon Charitable Fund, Melbourne, Victoria, Australia.

  • Competing interests: None.

  • Ethics approval: This study was approved by the hospital human research ethics committee.

  • Patient consent: Obtained.

Responses to this article

Free sample
This recent issue is free to all users to allow everyone the opportunity to see the full scope and typical content of EMJ.
View free sample issue >>

Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.

Navigate This Article